Submersible oil rig for drilling on bottom



July 24, 1956 TOWNSEND r AL 2,756,021

SUBMERSIBLB OIL RIG FDR DRILLING ON BOTTOM Filed Sept. 3, 1954 3 Sheets-Sheet l B 9 49 I F 7 I I 4 7 a 4 llll 7 fizz A? II III l 7 W 114 I/l/ 57 Y 53 36 f INVENTORS fix ZWA/swa BY flew/r1. flaws July 24, 1956 R. TOWNSEND ET AL 2,756,021

SUBMERSIBLE on. RIG FOR DRILLING on BOTTOM Filed Sept. 3, 1954 3 Sheets-Sheet 2 INVENTORS isx 7o'w/vss/m BY fZw/M' A fla /.5

y 24, 1956 R. TOWNSEND ET AL 2,756,021

SUBMERSIBLE OIL RIG' FOR DRILLING ON BOTTOM Filed Sept. 5, 1954 3 Sheets-Sheet 3 United States Patent 6 SUBMERSIBLE OIL RIG FOR DRILLING ON I I BOTTOM Rex Townsend, Greenwich, Conn., and Frank L. Davis, College Point, N. Y.

Application September 3, 1954, Serial No. 454,088

12 Claims. (Cl. 255-25) The invention herein disclosed relates to the underwater drilling of oil wells and is in the nature of a continuation-in-part of the invention of patent application Serial No. 186,394, filed September 23, 1950, Patent No. 2,691,272, issued October 12, 1954.

A distinguishing feature of the rigs covered by this patent is that drilling of the well is effected on bottom with rotary, drawworks, pumps and other heavy drilling equipment supported on solid bottom-forming ground, this made possible by a submersible form of barge having an enclosed derrick floor working chamber in the bottom of the same in sealing engagement with the submerged ground and having a tubular derrick column rising above water level and enabling drilling operations conducted at bottom level to be carried on under open-air conditions.

The present invention is particularly concerned with the anchorage and sealing of the barge to bottom, the

separation and release of the barge from bottom on completion of the well and possible return of the barge for reworking a well.

Also, it is proposed by the present invention to enable drilling operations being conducted in different depths of water and in allcases with safety and security and so as in the end to leave the ocean or water covered floor clear and free of obstructions which might interfere with navigation, fishing or other operations.

In connection with drilling at different depths, it is a purpose of the invention to construct the rig in sectional form so that it may be assembled in different sections or in different relations to enable drilling operations to be conducted at lesser or greater depths.

Important objects of the invention are to provide practical structure which will accomplish the foregoing at a reasonable cost and which will be of such durable character as to be usable repeatedly and indefinitely for different drilling operations.

The objects mentioned and others as will appear in the following specification have been attained by novel features of construction, combinations and relations of parts, all as hereinafter described and claimed.

The drawings accompanying and forming part of this specification illustrate certain practical features and embodiments of the invention but structure may be modified and changed as regards the present illustration, all within the true intent and broad scope of the invention as hereinafter defined and claimed.

Fig. 1 in the drawings is a broken vertical sectional view of one of the barges in submerged relation anchored and sealed in position for conducting drilling operations; Fig. 2 is a broken sectional view showing the well head parts left on bottom after removal of the barge;

Fig. 3 is a broken plan view of a portion of the subcellar floor of the barge, illustrating a method of applying a bottom cover plate;

Fig. 4 is a broken sectional view showing a portion of the barge as modified for drilling in shallow water;

' Fig. 5 is a broken part sectional view showing the barge parts combined for drilling in medium depth water on the order of fifty feet or so.

The barge shown in Figs. 1, 4 and 5 is like that of the Townsend and Davis Patent No. 2,691,272, as comprising a floatable and submersible barge structure 7 having an enclosed derrick floor constituting working chamher 8 and a tubular derrick forming column 9 rising therefrom.

The derrick column is open at the top to an elevated working platform 10 supported on the barge by corner towers 11.

A mounting for the rotary is provided in the floor of the working chamber at 12, above the cellar 13 and'sub cellar 14, and the working chamber is extended at the sides to accommodate drawworks, mud pumps and other equipment and to provide room for elevator and other communication purpose shafts 15 extending up to the elevated, above water working platform 10. ,7 A pontoon or flotation barge 16 is guided up over the columns of the working barge, and this may be raised and lowered and secured at diiferent levels in accordance with the patent to add weight or to add flotation to the barge.

Tubular guides 17 for the driving of anchoring and sustaining piles 18. are shown extending through the barge, Fig. 4. These may run up to the upper working platform or when superstructure is removed and the barge used in shallow water as indicated in Fig. '4, be cut off at the barge level.

With superstructure removed for'shallow drilling as in Fig. 4, a conventional form of derrick'may be mounted on the barge as indicated at 19, this derrick then serving as a replacement for the tubular derrick column 9. T

Fig. 5 shows how, if necessary or desirable, a short derrick structure 28 may be used even in the completely assembled barge combination to carry the crown block 21, this derrick structure mounted over the open upper end of the tubular derrick column.

Fig. 1 shows the concave bottom wall 22 of the barge about the cellar, having one or more pipe connections 23 therethrough for clearing this space and delivering cement which will leave a domed or rounded well head base 24, Fig. 2, when the well is completed and the barge floated away from the same.

' The cellar 13 immediately below the rotary table maybe pressurized, also the sub-cellar 14, with suitable air locks providing ingress and egress. I,

I Pressurized chambers 25 with air locks are indicated about the rim ofthe domed portion for enabling the setting of anchor hooks 26 in the well head formation.

These anchoring elements are shown as carried by plates 27 forming closures to operating openings 28 in the bottom of the chambers. These cover plates are bolted in place from the inside, as indicated at 29, and are left with the anchors in place in the well head, Fig. 2. The sub-cellar 14 is shown as having a working 0pening 30 in the bottom of the same closed by a plate 31 held in place by inside fastenings 32.

This cover plate carries a stufling box 33 projecting up through the opening, closed when not in service by a plug 34, Fig. 1, which can be driven down out of place by the inserted well casing 35. I

Fig. 1 shows the barge with the cover plates 27 and 31 in place as when floating to a location and being settled on bottom.

After drilling of a well is completed the fastenings 29 and 32 holding the cover plates in place may be released by a man working in the pressurized compartments 25 and pressurized sub-cellar 14, to release the barge from the well head and to leave anchorage hooks 26 with box set in the concrete.

Before letting go, anchor lines 36 may be connected with the hooks 26 and the usual or any special valves or Christmas tree fittings 37 be attached to the flow tubing. These final connections may include a length of flexible armored hose 38 running to a buoy, guyed by the anchor lines 36 as in the issued patent.

To enable closing of the pressurized chambers a construction likethat illustrated in Fig. 3 may be employed. In this view the center opening 30 in the bottom of the sub-cellar is shown as having notches 39 in opposite edges through which the cover plate 31 may be passed edgewise and then be manipulated into position over the outside of the opening, after which it can be secured by the bolts 32. Rings or handles 40 on the inner faces of the plate enable men to readily accomplish these operations.

While for medium and deep water drilling operations the barge may be operated with the fully assembled components illustrated in Fig. 5, it is possible for shallow water operations to use the same barge body, as illustrated in Fig. 4, with the then unnecessary superstructure, including upper working platform, supporting towers and tubular derrick column, removed.

In a typical deep water operation, the barge in floating condition, with float or pontoon 16 supplementing the lift of the barge, on arrival at location may have compartments floated to submerge and settle it on bottom. In this operation the flotation barge 16 may remain on the surface for stability and control of sinking operations.

If necessary or desirable, piles 18 may be driven down through the tubular guides 17. When the rig is stable and secure the flotation platform may be raised from the surface to load the sunken barge and reduce effects of tide and waves.

Casing pipe 35 may be centered in the stuffing box 33 and then lowered to force the closure plug 34 down and out of the stufiing box, thispipe being driven and set to a proper depth to seal the sub-cellar in place.

Loose material may then be cleared away, as by jetting, beneath the dome portion 22 of the bottom and then cement be introduced through pipe 23 to create the solid protective wellhead 24. At such time the anchorages 26, 27 will: have been set in place.

Normal drilling operations can then be proceeded with, the barge being, compartmented and otherwise constructed for mud tanks 41- and supply of other necessary materials and equipmennflotation and weight beingapplied as necessary by control of the upper barge or float 16.

On completion of drilling the necessary length of flexible hose 38 may be connected with the head of the well and stored Within the sub-cellar 14. Guy ropes 36 at this time will be attached to the anchor hooks 26 and stored in pressurized chambers 25; Then on removal of bolts 29 and 32, closureplates. 19 and 32 will be released and the barge free to'rise when submergence tanks are cleared. Before this time the flotation platform may be lowered and coupled to the barge as it rises to provide stability and full flotation;

The barge in rising from the concrete base, will leave a substantial domed structure having the cellar formation 42 at the center of the same;

When the barge is free of the bottom, closure plates 27 and 31 may be applied overthe working openings in the bottom of the barge, as previously described.

The barge then, with bottom openings closed, may be floated off to another location, be submerged and drilling operations be repeated.

The concrete dome provides a firm, solid base and foundation for drilling on bottom and an anchorage for holding the rig white drilling operations are going on and for securing the rigagainst the forces of wind and wave, including thoseof hurricane extent.

While solidly held to the bottom for drilling purposes,

the rig can be readily released andfloated away, leaving.

only the low, rounded mound which at bottom level will not interfere with navigation, fishing or other pursuits.

The doomed well head formation provides an anchorage readily located and to which a rig may be readily returned and after being centered thereover, may be lowered and reconnected for continued drilling, cleaning or re-working a well.

The concrete for the well head, instead of being poured before, may be poured after the well is brought in.

The tubular guides 17 for the piles may be cut off at or below the bottom level of the barge, depending on conditions encountered in leveling and anchoring the barge on bottom.

While generally it may be considered best to mount the rotary on the floor of the working chamber, as indicated at 12, the sectional character of the rig enables the rotary being located at different levels, for instance, possibly at the top level of the barge, or if a derrick is superposed as at 19, 20, Figs. 4 and 5, at the floor level of such derrick structures.

The barge, submersible as it is to provide a solid drilling foundation and form for a permanent bottom level well head, constitutes a basic structure for interchangeable use in shallow intermediate or deep Water locations.

Asshown in Fig. 4, the basic barge structure may be used for drilling on bottom in water so shallow as not to flood the barge. In such case, with the tubular derrick column removed, an ordinary oil well derrick may be mounted directly on the barge deck. In this way the barge is adaptable for use with ordinary oil well drilling equipment.

At times or under certain conditions, it may be desirable to locate the rotary at a higher level and still operate from the power source down in the barge. This may be accomplished by mounting the rotary on staging or a platform set up in the tubular derrick column at the desired height and extending a power take-off drive, such as shaft or chain, from the rotary drive motor down in the working chamber of the barge up to the rotary mounted in the derrick column.

What is claimed is:

1. Submersible rig for drilling on underwater bottom ground, comprising a submersible and refloatable barge having an enclosed working chamber from which drilling operations can be conducted when the barge is on bottom, said barge having an upwardly concave bottom wall to seat on underwater bottom-ground, means for introducing cement beneath said concave bottom wall to leave a domed well head formation on bottom when the barge is refloated, said bottom wall having access openings therein, closure plates over the outside of said openings and fastcnings for securing said closure plates over said openings and accessible within the barge, and releasable to leave said plates embedded in the well head formation when the barge is refioated away from a finished well.

2. The invention according to claim 1, with a downwardly projected cellar at the center of said concaved bottom wall for leaving a cellar depression in the domed well head formation.

3. The invention according to claim 2, and in which one of said access openings is in thebo-ttorn of said cellar and in which the closure plate over said opening is provided with a stuffing box for easing pipe.

4. The invention according to claim 1-, with pressurized chambers in the barge providing access to said openings.

5. The invention according to claim 1, in which said openings have notched edges and said closure plates are of a size to he slipped edgewise through the notches in the openings. into position over the outside of the openings.

6. The invention according to claim 1, with anchorages carried by certain of the closure plates, in position for embedment in the well head formation.

7. The invention according to claim 1, with cellar and sub-cellar chambers extended beneath the enclosed working chamber into the center portion of the concaved bottom wall of the barge.

8. The invention according to claim 1, with a cellar chamber beneath the working chamber and a tubular derrick column extending from the top of the working chamber.

9. The invention according to claim 1, including the further feature of a derrick rising from said enclosed working chamber, constructed and arranged to enable drilling operations to be conducted under open air conditions.

10. The invention according to claim 1, with a pressurized sub-cellar chamber extending downward from said working chamber for enabling men to work therein in the submerged condition of the barge.

11. The invention according to claim 1, including the further feature of a tubular derrick column rising from said enclosed working chamber to above level of water in which the rig is used and open at the top to enable drilling operations to be conducted on bottom with the working chamber under open-air conditions.

12. The invention according to claim 1, with tubular pile guides extending down through the barge about said working chamber for enabling the driving of piles for levelling or anchoring the barge at points about the working chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,239,026 Neier Sept. 4, 1917 1,465,664 Griesser Aug. 21, 1923 2,051,926 Weiner Aug. 25, 1936 2,622,404 Rice Dec. 23, 1952 2,669,846 Shannon Feb. 23, 1954 2,691,272 Townsend et al. Oct. 12, 1954 2,699,321 Nelson Ian. 11, 1955 

1. SUBMERSIBLE RIG FOR DRILLING ON UNDERWATER BOTTOM GROUND, COMPRISING A SUBMERSIBLE AND REFLOATABLE BARGE HAVING AN ENCLOSED WORKING CHAMBER FROM WHICH DRILLING OPERATIONS CAN BE CONDUCTED WHEN THE BARGE IS ON BOTTOM, SAID BARGE HAVING AN UPWARDLY CONCAVE BOTTOM WALL TO SEAT ON UNDERWATER BOTTOM GROUND, MEANS FOR INTRODUCING CEMENT BENEATH SAID CONCAVE BOTTOM WALL TO LEAVE A DOMED WALL HEAD FORMATION ON BOTTOM WHEN THE BARGE IS REFLOATED SAID BOTTOM WALL HAVING ACCESS OPENING THEREIN, CLOSURE PLATES OVER THE OUTSIDE OF SAID OPENINGS AND FASTININGS FOR SECURING SAID CLOSURE PLATES OVER SAID OPENINGS AND ACCESSIBLE WITHIN THE BARGE, AND RELEASABLE TO LEAVE SAID PLATES EMBEDDED IN THE WALL HEAD FORMATION WHEN THE BARGE IS REFLOATED AWAY FROM A FINISHED WELL. 